back titration

简明释义

回滴定

英英释义

例句

1.The chemist performed a back titration 回滴定 to find out how much acid was present in the sample.

化学家进行了回滴定 back titration以找出样品中存在多少酸。

2.Using back titration 回滴定, the students were able to calculate the amount of unreacted reagent left in the flask.

通过使用回滴定 back titration，学生们能够计算出烧瓶中未反应试剂的数量。

3.The method of back titration 回滴定 is particularly useful when the endpoint of a direct titration is hard to detect.

当直接滴定的终点难以检测时，回滴定 back titration 方法特别有用。

4.When analyzing the reaction, we opted for back titration 回滴定 because it provided more accurate results than direct titration.

在分析反应时，我们选择了回滴定 back titration，因为它比直接滴定提供了更准确的结果。

5.In the laboratory, we often use back titration 回滴定 to determine the concentration of a substance that is difficult to measure directly.

在实验室中，我们经常使用回滴定 back titration来确定难以直接测量的物质浓度。

作文

Back titration is a valuable analytical technique used in chemistry to determine the concentration of a substance in a solution. This method is particularly useful when the substance being analyzed is either insoluble or does not react directly with the titrant. In essence, back titration (反滴定) involves adding an excess of a standard solution to react with the analyte, and then the unreacted portion of this standard solution is titrated with another solution to find the original concentration of the analyte.To illustrate the concept, consider a scenario where we want to determine the amount of calcium carbonate (CaCO3) in a sample. Calcium carbonate is not soluble in water, making direct titration challenging. Instead, we can use back titration (反滴定) to achieve our goal. First, we would add an excess of hydrochloric acid (HCl) to the sample containing calcium carbonate. The reaction between HCl and CaCO3 will produce calcium chloride, water, and carbon dioxide gas. Once the reaction is complete, we will have some unreacted HCl left in the solution.Next, we need to determine how much HCl remains unreacted. To do this, we perform a second titration using a sodium hydroxide (NaOH) solution of known concentration. By titrating the excess HCl with NaOH, we can calculate the amount of HCl that reacted with the calcium carbonate. From this information, we can backtrack to find the original amount of calcium carbonate present in the sample.The advantage of using back titration (反滴定) lies in its ability to provide accurate results even when dealing with substances that are difficult to titrate directly. It is also a preferred method when the endpoint of the direct titration is hard to identify, such as in the case of colored solutions or precipitates. Furthermore, back titration (反滴定) allows for the analysis of samples that may contain impurities or that react slowly, which could lead to inaccuracies in a direct titration approach.In addition to its practical applications in laboratory settings, back titration (反滴定) is also widely used in various industries, including pharmaceuticals, food safety, and environmental monitoring. For example, in the pharmaceutical industry, it is crucial to ensure that active ingredients in medications are present in the correct concentrations. Using back titration (反滴定), chemists can confirm the potency of these compounds effectively.Moreover, understanding the principles behind back titration (反滴定) enhances students' grasp of stoichiometry and chemical reactions. It encourages critical thinking and problem-solving skills as they must carefully plan their experiments and interpret their results. As students progress through their chemistry education, mastering techniques like back titration (反滴定) prepares them for more complex analyses and fosters a deeper appreciation for the subject.In conclusion, back titration (反滴定) is an essential tool in the chemist's toolkit. Its versatility and accuracy make it a preferred choice for many analytical challenges. By employing this method, chemists can gain insights into the composition of substances that would otherwise be difficult to analyze, ultimately contributing to advancements in science and industry.